Strengthened door for a blast-resistant cargo container

ABSTRACT

An strengthened door for an blast-resistant cargo container includes a door panel horizontally slidably mounted on the cargo container. The door panel has an upper side, a lower side, a first vertical side and a second vertical side each hooked on the cargo container to provide overlapping joints to effectively limit blast damage to the inside of the cargo container and prevent an aircraft from being damaged.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a strengthened door, and more particularly to a strengthened door for the cargo container need to resist explosive blast.

[0003] 2. Description of Related Art

[0004] A cargo container must have a door pivotally mounted on it to selectively close the cargo container for loading and unloading goods. However, the conventional door for a cargo container does not have a strengthened design or device to resist an explosive blast.

[0005] Over a decade, airplanes have become a primary target for terrorist attack, and many people have lost their lives in plane crashes due to terrorist bombs attached in checked baggage. To prevent those tragedies from happening, a lot of efforts have been made in the field of blast-resistant containers.

[0006] According to analysis and experiments, the blast-resistant cargo container need to take the blast pressure tens of times greater than the payload of the conventional cargo container. Thus, although the door of blast-resistant container is moveable, it also needs to take the same large pressure as the other panels which are firmly connected to each other to comprise the container. Therefore, the door of conventional cargo container without strengthened design is very vulnerable to the explosive blast.

[0007] Many blast-resistant cargo containers have been granted patents in the USPTO, such as U.S. Pat. Nos. 5,599,082, 6,019,237, and 6,237,793. U.S. Pat. No. 5,599,082 is a hardened aircraft unit load device, which door has a pair of opposed crooked fingers attached along part of the edge of the door to establish a bite for strongly connecting the door panel and its adjacent panels. But the door is not easy to operate and there are only three (not all four) edges of the door can be strongly connected. It is easy to failure at the non-strongly connected edge when exploded.

[0008] U.S. Pat. No. 6,019,237 is a modified container using an inner bag to resist the blast. The bag member includes multiple overlapping door frame folds to reduce the force between the door and the bag opening frame. However, the unreliable mechanism may result in that the length of the connector between the door and the opening frame is too short to resist explosive blast.

[0009] U.S. Pat. No. 6,237,793 is an explosion resistant aircraft cargo container having a door with two side edges and a bottom edge that can securely connect to its adjacent panels. But the door panel is flexible. When opened, the door panel has to be folded several times to complete the operation. Obviously, there are some damages occurred inside the door panel along the folds after certain times of operation. And that is the very serious situation for the blast-resistant cargo container because the crew couldn't see the damage from the outside when interior damages are occurred.

[0010] The present invention has arisen to mitigate and/or obviate the disadvantages of the cargo container door, no matter the conventional or blast-resistant cargo container just mentioned above.

SUMMARY OF THE INVENTION

[0011] For the blast-resistant cargo container, the present invention provides a strengthened door which can be strongly connected to its adjacent panels in all four edges and can save operation space.

[0012] To achieve the objective, the strengthened door in accordance with the present invention includes a door panel horizontally slidably mounted on the cargo container. The door panel has an upper side, a lower side, a first vertical side and a second vertical side each hooked on the cargo container to provide overlapping joints to effectively limit blast damage to the inside of the cargo container and prevent the aircraft from being damaged.

[0013] Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014]FIG. 1 is a perspective view of a blast-resistant cargo container in accordance with the present invention;

[0015]FIG. 2 is a front plan view of a strengthened door in FIG. 1;

[0016]FIG. 3 is a cross sectional side plan view of the strengthened door along line 2-2 in FIG. 2;

[0017]FIG. 4 is a cross sectional side plan view of the strengthened door along line 3-3 in FIG. 2;

[0018]FIG. 5 is a cross sectional top plan view of the strengthened door along line 4-4 in FIG. 2;

[0019]FIG. 6 is a cross sectional top plan view of the strengthened door along line 5-5 in FIG. 2; and

[0020]FIG. 7 is an enlarged perspective view of a hinged latch of the strengthened door in FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION

[0021] With reference to the drawings and initially to FIGS. 1-6, a strengthened door for a blast-resistant cargo container in accordance with the present invention comprises a door panel (20), an opening frame (not numbered). The opening frame (not numbered) is mounted on the adjacent panels of the door panel, i.e. around an opening in the cargo container (10). The door panel (20) adapted to be horizontally slidably mounted on the opening frame (not numbered) to close the cargo container (10). The opening frame is comprised of an upper frame (12), a lower frame (14), a first vertical frame (160), and a second vertical frame (30). The door panel (20) includes an upper side (22), a lower side (24), a first vertical side (26), and a second vertical side (28) which can be strongly connected to an upper frame (12), a lower frame (14), a first vertical frame (160), and a second vertical frame (30) respectively. The free end (302) of a second vertical frame (30) must be arbitrarily translatable and rotatable relative to its fixed end and can be operated by crew to securely close the door panel.

[0022] With reference to FIG. 3, the upper frame (12) of the cargo container (10) has an upper frame hook (120) extending inward from the upper frame (12), and the hook-like upper side (22) of the door panel (20) extend outwardly. The upper frame hook (120) of the cargo container (10) and the upper side (22) of the door panel (20) are slidably interlocked. The door panel (20) is closed to provide a great tensile force when a bomb exploded in the cargo container (10). This connecting method provides a complete blast resistant to the cargo container (10).

[0023] With reference to FIG. 4, a groove (140) is defined horizontally in the lower frame (14). The lower side is formed by a connecting member (24) which is attached securely to the door panel (20). The connecting member (24) includes a lip (240) which is extended from a vertical lower edge of the connecting member (24). The lip (240) of the connecting member (24) slidably engages the groove (140) in the lower frame (14) of the cargo container (10) to provide a good connection between the lower frame (14) and the connecting member (24) of the door panel (20).

[0024] With reference to FIG. 5, the first vertical frame is formed by a vertical frame hook (160) and is attached to the side panel (16). The first vertical side of the door panel (20) is formed by a first side hook (26) vertically. The first side hook (26) of the door panel (20) is selectively engaged to the vertical frame hook (160) when the door panel (20) closes the cargo container (10).

[0025] With reference to FIGS. 6 and 7, the second vertical frame is vertically formed by a hinged latch (30) and is mounted on one side of the cargo container (10) to hold the door panel (20) in place. The hinged latch (30) has two vertical extruded bars (300) which pivotally connected to each other at one side and to the hinge hook (302) and the fix end respectively at the other side by pivot pins (304). A hinge hook (302) is vertically formed on a free end of the hinged latch (30). A second vertical side of the door panel (20) is formed by a second side hook (28) vertically. The second side hook (28) provides a conjugation to fit the hinge hook (302) and to hold the door panel (20) in place when the door is closed.

[0026] To operate the strengthened door of the present invention, the door panel (20) slides on the upper frame hook (120) and the groove (140) in the lower frame (14) of the cargo container (10). With reference to FIG. 2, the blast-resistant cargo container (10) is closed by pulling the door panel (20) toward the hinged latch (30) and connecting the hinge latch (30) to the second side hook (28). When the door panel (20) is moved to a closed position, the first side hook (26) is hooked to the first vertical frame (160) at the same time which is conjugated to the first side hook (26) and connects to the the panel (16).

[0027] The engagement between the strengthened door and the cargo container (10) can effectively limit blast damage to the inside of the cargo container and prevent the aircraft from being damaged. In order to open the strengthened door, the hinge hook (302) must be moved to the direction of the door panel (20) firstly to relax the lock, and then rotate away the hinge latch (30) to let it opened. But an exploding blast generates a radial pressure that impacts the strengthened door. This pressure will let the hinge latch (30) stretched and cause that the hinge hook trend to be pulled to the reverse direction. And it will result in the door to be closed much tight. Thus, this strengthened door can be strongly connected to its adjacent panels in all four edges and can save operation space. Therefore, this invention can effectively hold the blast damage inside the cargo container.

[0028] Although the invention has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the invention as hereinafter claimed. 

What is claimed is:
 1. A strengthened door installed on an opening frame which is mounted around an opening in a blast-resistant cargo container comprise: a door panel; an upper and a lower side of said door panel which can be connected strongly to the upper and lower frames of said opening frame but said door panel can still slide on said frames; a first vertical side of said door panel which can be connected strongly and continuously or piecewise continuously on the first vertical frame of said opening frame; and a second vertical side of said door panel which can be connected strongly and continuously or piecewise continuously on the second vertical frame of said opening frame and the free end of a second vertical frame can be arbitrarily translatable and rotatable relative to its fixed end and can be operated by crew to securely close said door panel, to meet the blast-resistant requirements that the door is moveable and the connecting between the door panel and its adjacent panels can be as strong as other non-moveable connectings between each two panels.
 2. The strengthened door as claimed in claim 1, wherein said lower side of said door panel comprises a connecting member attached to said door panel, and this connecting member have a lip extending from a vertical lower side of said connecting member, said lip adapted to be slidably hooked in a groove that is defined in said lower frame of the cargo container.
 3. The strengthened door as claimed in claim 1, wherein said upper side of said door panel comprises an upper hook, which is adapted to be slidably hooked on an upper frame hook that is defined in said upper frame of the cargo container.
 4. The strengthened door as claimed in claim 3, wherein said upper hook of the door panel extends outward from said upper side of the door panel and said upper frame hook extends inward from said upper frame.
 5. The strengthened door as claimed in claim 1, wherein said first vertical side of said door panel comprises a first side hook vertically, which is adapted to selectively engage a vertical frame hook that being a conjugate hook of said first side hook and defined for said first vertical frame.
 6. The strengthened door as claimed in claim 1, wherein said second vertical side of said door panel comprises a second side hook vertically, which is adapted to selectively hook a hinge hook formed on the free end of a hinged latch, said hinge latch is defined for said second vertical frame and can be operated by crew to securely close the door panel.
 7. The strengthened door as claimed in claim 1, wherein said hinge latch has two vertical extruded bars, said two vertical extruded bars are pivotally connected to each other at one side and to said hinge hook and the fix end respectively at the other side by pivot pins. 